Rusty's 3.5" add a leaf: any good?

[Yogi]

Another nooby inquiry:
Rusty's has a 3.5" add a leaf kit. Does this thing actually do 3.5 inches of lift? Seems like a lot of lift for an add a leaf. If it's the real deal, how about this for an el cheapo lify: this kit, plus a 1" extended shackle in front and a one or two inch block in the back? Should be at least 4 inches of lift, right? Or am I missing something?
There's got to be a catch...

[RamJetFSJ]

They have a 2” all add a leaf kit.

The 3.5” add a leaf kit uses full replacement springs in the front, and the 2” add a leaf plus blocks in the rear.

I would be surprised if you get a full 2” from the add a leafs.

[Stuka]

I would advise against lift shackles in front. They really mess with the steering and cause a flighty steering feel.

[Yogi]

Yeah, if such a combo was a good way to go, then everybody would be doing it, right?